This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 20 |
| 7 | 131 |
| 8 | 815 |
| 9 | 5142 |
| 10 | 36800 |
| 11 | 272093 |
| 12 | 2077909 |
| 13 | 16176607 |
| 14 | 127997683 |
| 15 | 1025727646 |
| 16 | 8310377815 |
| 17 | 68217725764 |
| 18 | 560527576100 |
| 19 | 4556993996246 |